It was a great operation, outlasting other regular scheduled steam in Poland by over a decade. Credit has to go to Howard Jones and the Wolsztyn Experience people for keeping it going all these years.
I was there in the winter of 2006, unforgettable experience running commuter trains in the dead of winter, especially at 5:30 am! Interesting to run the injector and set the reverser in the dark.
Re. the single ditch light: It is the signal that the engine is running light in the yard limits. After the train has stopped at the end of it's run, the other lights are turned off and then the engine uncouples to get serviced.
The operation in Wolsztyn is still active, but now for excursion service through TurKol.
There is (always?) a chance that regular steam passenger will start up again. Money is the issue. Keep in mind that the lines out of Wolsztyn (to Lezno and Posnan) are really branch lines with most passenger traffic handled by diesel rail cars.

Chris